does not mean that they have to take any steps to contribute the changes they’ve made to the upstream project.

You’re partially right. They don’t have to “contribute back” by submitting pull requests or something similar.

They do have to contribute back by making their changes publicly available. Whether upstream uses those changes is up to them.

I’m going to ignore you now since all of your replies have shown me you’re a moron. Peace.

So let them do that. Why should we be doing their dirty work for them?

Unless we’re stupid.

Businesses can already create their own forks of GPL-licensed software and not contribute their changes to the upstream project

No they can’t, at least not legally. Part of using GPL software is that you need to include the GPL with any changes you make.

It’s the entire point of the license and the concept behind copyleft.